Outline

Objective: Little current data is available regarding seizure control in multimodally-treated patients with cerebral arteriovenous malformations (AVMs). The goal of this retrospective study was to compare seizure outcome in patients undergoing either surgical treatment alone or preoperative embolization and subsequent surgical treatment for a supratentorial AVM.

Methods: All patients treated between January 1999 and December 2008 for a supratentorial arteriovenous malformation were identified through operative logs, protocols of interdisciplinary team conferences and the database kept by the Outpatient Clinic of the Clinical Department of Neurology. Entry variables included demographic data, presenting symptoms, duration of seizure history (if applicable), angioma location, angioma classification (as determined by the Spetzler/Martin classification) and treatment modality. Outcome was determined using the modified Engel classification (Classes 1A to 4C).

Results: Of 42 patients (24 females, mean age at treatment: 38 years), Spetzler-Martin grades I (n = 13), II (n = 14), III (n = 12), and IV (n = 3). AVM location was the temporal lobe (n = 9), the non-temporal hemisphere (n = 30), and deep (n = 3). 41 patients were treated either by surgery alone (n = 21), by embolization and surgery (n = 14), by embolization alone (n = 3), by embolization and radiotherapy (n = 2) and by surgery and radiotherapy (n = 1). 18 (44%) experienced seizures before treatment. Only one patient had experienced more than five seizures prior to treatment. Mean age at seizure onset was 36 years (range 14 to 73 years). Mean duration of seizure history was 17 months (range 1 to 132 months). 16 (89%) obtained an outcome Engel class IA. An unfavorable outcome (Engel classes IVC and IVD, respectively) was observed in 2 patients (11%). Six patients (15%) who had been seizure-free before treatment experienced new seizures after treatment, starting 26 months (mean, range 4 to 74 months) after treatment. There was no difference between the patients treated either with surgery alone (n = 21) or those with preoperative embolization and surgery (n = 14). In both groups, 14% experienced new seizures (n.s.).

Conclusions: Seizure outcome for patients presenting with a supratentorial AVM and seizures is favorable with modern treatment methods. The incidence of new postoperative seizures in this series is within the known literature range. Preoperative embolization does not seem to be an additional risk factor for postoperative seizures.